21
Jan
Genetically Weakened Skin Barrier Allows for Easier Absorption of Toxic Chemicals
(Beyond Pesticides, January 21, 2021) A new Swedish study in Environmental Health Perspectives demonstrates individuals with genetically weakened skin barrier protection experience higher rates of toxic chemicals (i.e., pesticides) absorption through the skin. Studies provide evidence that filaggrin genetic mutations can exacerbate the impacts of chemicals upon dermal (skin) exposure, causing various skin diseases like dermatitis and other chemical-related effects like asthma and cancer. Filaggrin is a protein that is critical to skin cell structure or epidermal homeostasis. Just as excessive exposure to UV light can cause skin discoloration and cancer, excessive dermal contact with these toxic chemicals can cause a range of adverse reactions, including dermatitis, allergic sensitization, and cancer. Dermal exposure is the most common pesticide exposure routes, compromising 95 percent of all pesticide exposure incidents. Furthermore, many pesticides contain chemicals that act as sensitizers (allergens). Therefore, it is essential to mitigate direct skin contact with these toxic chemicals and enforce proper application protocol.
Dermal chemical exposure is an increasing concern for occupational (work-related) health. Likewise, people experience dermal exposure to chemicals from everyday products like cleaning supplies, personal care products, agricultural chemicals, fabrics, non-stick cookware, and general airborne pollution. Furthermore, skin disease risks can increase among those with less protection from chemical exposure due to genetics.
The study’s results demonstrate individuals with FLG null mutations and low CNV are more susceptible to increased dermal uptake and absorption of chemicals. Researchers find that pesticide levels are two times higher in individuals with FLG null mutations. Therefore, increased chemical absorption can have implications for human health. It puts those with this mutation at a higher risk of developing latent diseases like cancer and endocrine disruption from higher internal pesticides levels. FLG null mutations are relatively common, especially among people of European descent. Therefore, implementing policies that limit dermal exposure to toxic chemicals can safeguard human health.
The study highlights the importance of understanding the effect dermal exposure to chemicals has on human health, particularly among genetically vulnerable individuals. Study researchers state, “Protection of individuals with a high dermal absorption is important because dermal uptake is a major route of environmental exposure to chemicals. New chemicals are continuously being added to consumer products all over the world. Still, there is limited research on the role of genetics in dermal chemical exposure and absorption.”
Skin barrier structure and function depend on the filaggrin protein, and “loss-of-function (null) mutations” in the filaggrin gene (FLG) may contribute to an increase in dermal absorption of chemicals. The study aims to explain whether alterations in the gene FLG change the intensity of dermal chemical uptake.
To determine carriers of the loss-of-function mutation (FLG null) among the general population in Sweden, researchers used quantitative PCR. Subsequently, the researchers exposed 23 FLG null carriers and 31 wildtype (wt) or “normal” FLG carriers to three common environmental organic compounds. The compounds include pyrene (polycyclic aromatic hydrocarbon), pyrimethanil (fungicide), and oxybenzone (ultraviolet-light absorber in sunscreen). Urinary analysis using liquid-chromatography mass-spectrometry measured the concentration of the three chemicals and their metabolites 48 hours after exposure. Researchers performed a toxicokinetic analysis between FLG null and wildtype carriers to determine the rate chemicals will enter the body and excrete and metabolize once inside. Lastly, researchers used long-range PCR to determine FLG gene copy number variants (CNVs) that contain copies of 10, 11, or 12 repetitive sequences encoding filaggrin monomers (combined compounds that duplicate).
The study finds a significant difference between dermal absorption and uptake of chemicals, with FLG null carriers having lower CNV and shorter lag time for skin absorption than non-carriers. Moreover, individuals with the FLG null variant expel 18 percent and 110 percent more metabolite than non-carriers with low and high CNV, respectively.
The skin responds to numerous external stimuli that can change its morphological (shape/structure), physiological (function), and histological (tissue) properties. Some stimuli responses are typical, including skin exposure to sunlight (UV-light) for tanning or wrinkling in water. However, exposure to excessive stimuli like environmental contaminants can propagate adverse, permanent changes to the skin.
Researchers conclude, “Gaining knowledge about what FLG null mutations and CNV mean for dermal absorption is important to better understand skin barrier function and the preventive and protective measures and guidelines that should be implemented by authorities, caregivers, and employers to decrease skin exposure and skin absorption, such as imposing limit values for dermal exposure to consumer products and occupational chemicals and advising people to reduce their dermal exposure to certain chemicals.”
People encounter toxic chemicals daily. However, frequent misuse of pesticides, including the excessive use of cleansing agents against coronavirus, exacerbate chemical exposure risks. Hence, global leaders and individuals alike must decrease the reliance on toxic chemicals to safeguard against disease. Public health officials should carefully examine chemicals in everyday products to ensure they do not pose any unnecessary health dangers.
Beyond Pesticides tracks the most recent studies related to pesticide exposure through our Pesticide Induced Diseases Database (PIDD). This database supports the clear need for strategic action to shift away from pesticide dependency. For more information on the multiple harms of pesticides, see PIDD pages on body burdens, endocrine disruption, cancer, and other diseases.
Additionally, replacing pesticides with organic, non-toxic alternatives is crucial for safeguarding public health, particularly communities vulnerable to pesticide toxicity. For more information on how organic is the right choice, see Beyond Pesticides’ webpage, Health Benefits of Organic Agriculture. Furthermore, visit Beyond Pesticides’ webpage on Disinfectants and Sanitizers and Least Toxic Control of Pests In the Home and Garden to learn more about safer, non-toxic pesticide alternatives.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Very informative!
January 26th, 2021 at 7:28 am